<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
	<title></title>
	<style type="text/css">
	    *{
	    	margin: 0;
	    	padding: 0;
	    }
		.box,.left{
			height: 200px;
			text-align: center;
		}
		.box{
			width: 100%;
			float: left;
		}
		.right{
            margin-left: 200px;
            background: green;
		}
		.left{
			width: 200px;
			background: red;
			float: left;
			margin-left: -100%;
		}
	</style>
</head>
<body>
   <div class="box">
   	<div class="right">右侧自适应右侧自适应右侧自适应</div>
   </div> 
   	<div class="left">左</div>
    <audio controls="">
    	<source src="xxx.mp3" type="audio/mpeg">
    </audio>
    <video width="" height="" controls="">
    	<source src="xxx.mp4" type="video/mp4">
    </video>
</body>
</html>